CT Slice: Radiologists’ Role in Diagnosing Aortic Dissection
By Rebekah Moan
Radiology Today
Vol. 26 No. 8 P. 5
Aortic dissections don’t affect as many people as heart attacks or strokes—approximately 13,000 people die annually in the United States1—but the consequences of the condition can be far deadlier, and radiologists have an important part to play in reducing mortality. A tear in the inner layer of the aorta can happen at any time, but there are certain risk factors that increase the chances of an aortic dissection. They occur across every age and demographic, but the risk increases for people who have the following:
• hypertension;
• atherosclerosis;
• aortic aneurysm;
• aortic valve disease;
• congenital heart conditions; or
• a family history of aortic dissection.
Being aware of the risk factors and tracking patients matters because about 50% of aortic dissection patients die before reaching a hospital, and up to 80% of patients could survive with prompt diagnosis and treatment.2 Radiologists play a key role in diagnosing these devastating injuries.
There is no routine screening program for the population writ large, but conducting targeted screening is crucial, according to Kim Eagle, MD, the director of the cardiovascular center at the University of Michigan Health System. People with family history, genetic syndromes, a bicuspid valve, or longstanding hypertension should be imaged regularly. Surveillance may involve echocardiography, CT, or MRI. The imaging modality depends on the patient’s anatomy, surgical history, and the physician’s need to see the entire aorta.
Radiologists should be on the lookout for a large or abnormal aorta, widening or abnormal contour on a chest X-ray, and aortic dilation. The diameter should be noted at specific locations along with the true and false lumen because a false lumen indicates a high potential for an aortic dissection.
“There isn’t a single surveillance schedule that works for everyone,” Eagle says. “Surveillance is lifelong, and the timing depends on factors like diagnosis, aortic size and rate of growth, genetic background, and any prior surgery. Importantly, at-risk patients need regular, consistent imaging, with intervals tailored by their care team.”
That said, about 1% of the population has a bicuspid aortic valve, and up to 40% of those patients will go on to develop an aortic aneurysm, according to Eagle. “Careful measurement of the aorta during imaging, whether echo, CT, or MRI, can pick this up before symptoms appear,” he adds. “Identifying and tracking these patients over time is a way radiologists can contribute to prevention.”
Symptomatic Patients
Imaging for symptomatic patients is a bit different than for people who need routine imaging. First, it’s important to recognize that the symptoms of an aortic dissection are similar to a heart attack or stroke: chest pain, shortness of breath, low blood pressure, trouble talking, etc. But misdiagnosis can be deadly. For symptomatic patients, CT angiography is the first-line test. “It’s quick, widely available, and provides a clear look at the aorta,” Eagle says.
However, CT angiography isn’t the only option. MRIs can be valuable for younger patients and those who need repeat imaging because they avoid radiation and can show both anatomy and blood flow. Lastly, although designed as an aortic screening tool, calcium score CTs include the thoracic aorta. Radiologists can add significant value by reporting the aortic size, especially if it’s prominent, because it is an indicator of increased dissection risk.
Aortic dissection can present in many different settings—emergency departments, OB/GYN clinics, primary care offices, cardiology practices—so it’s important for all providers to keep aortic dissection in mind when patients present with symptoms, family history, etc, according to Eagle. “Building stronger communication across specialties ensures patients are flagged early and get to imaging and treatment without delay,” he says.
Future Developments
The future for aortic dissection diagnosis and treatment is trending toward the broader themes emerging in all of medicine: personalization and AI. As genetic testing becomes more advanced, the health care community is learning that specific genes can influence how the aorta behaves, which is helping health care providers be more precise in estimating the right time for surgery.
“Looking ahead, these insights could also support more personalized medical treatments and imaging protocols so that both therapy and surveillance are tailored to an individual’s genetic risk,” Eagle says. “Radiology will be central to putting that precision into practice.”
In terms of AI, Eagle sees the possibility of AI-assisted detection on routine CT scans helping auto-flag abnormal aortic diameters and even phenotypes. “There’s also early exploratory work in facial analytics that may suggest syndromic risk, right at triage,” he says. “These innovations could give radiologists powerful new tools to identify at-risk patients earlier and more reliably.”
Regardless of what happens in the future, right now, radiologists can and do have a central role at every step of aortic dissection diagnosis. Radiologists can be the first to spot aortic enlargement or dissection and thus influence patient management and treatment.
“Clear, prominent reporting also ensures that referring clinicians act on aortic findings rather than overlook them,” Eagle says. “Lastly, radiology also helps identify patients whose family members may benefit from genetic testing and surveillance. By reinforcing consistency in measurement, tracking growth over time, and ensuring patients don’t get overlooked, radiology supports the long-term continuity of care that saves lives.”
— Rebekah Moan is a freelance journalist and ghostwriter based in Oakland. Her specialties are health care and profiles.
References
1. Khalid N, Abdullah M, Afzal M, et al. Aortic dissection related mortality trends in the United States from 1999-2020 — a CDC WONDER database analysis. JACC. 2024;83(13_Supplement):2369. https://doi.org/10.1016/S0735-1097(24)04359-6
